A computer-aided detection system in the everyday setting of diagnostic, screening, and surveillance colonoscopy: an international, randomized trial.

BACKGROUND: Computer-aided detection (CADe) has been developed to improve detection during colonoscopy. After initial reports of high efficacy, there has been an increasing recognition of variability in the effectiveness of CADe systems. The aim of this study was to evaluate a CADe system in a varied colonoscopy population. METHODS: A multicenter, randomized trial was conducted at seven hospitals (both university and non-university) in Europe and Canada. Participants referred for diagnostic, non-immunochemical fecal occult blood test (iFOBT) screening, or surveillance colonoscopy were randomized (1:1) to undergo CADe-assisted or conventional colonoscopy by experienced endoscopists. Participants with insufficient bowel preparation were excluded from the analysis. The primary outcome was adenoma detection rate (ADR). Secondary outcomes included adenomas per colonoscopy (APC) and sessile serrated lesions (SSLs) per colonoscopy. RESULTS: 581 participants were enrolled, of whom 497 were included in the final analysis: 250 in the CADe arm and 247 in the conventional colonoscopy arm. The indication was surveillance in 202/497 colonoscopies (40.6 %), diagnostic in 199/497 (40.0 %), and non-iFOBT screening in 96/497 (19.3 %). Overall, ADR (38.4 % vs. 37.7 %; P = 0.43) and APC (0.66 vs. 0.66; P = 0.97) were similar between CADe and conventional colonoscopy. SSLs per colonoscopy was increased (0.30 vs. 0.19; P = 0.049) in the CADe arm vs. the conventional colonoscopy arm. CONCLUSIONS: In this study conducted by experienced endoscopists, CADe did not result in a statistically significant increase in ADR. However, the ADR of our control group substantially surpassed our sample size assumptions, increasing the risk of an underpowered trial.

Technical failure during colorectal endoscopic full-thickness resection: the "through thick and thin" study.

BACKGROUND: Endoscopic full-thickness resection (EFTR) is an effective and safe technique for nonlifting colorectal lesions. Technical issues or failures with the full-thickness resection device (FTRD) system are reported, but there are no detailed data. The aim of our study was to quantify and classify FTRD technical failures. METHODS: We performed a retrospective study involving 17 Italian centers with experience in advanced resection techniques and the required devices. Each center shared and classified all prospectively collected consecutive failures during colorectal EFTR using the FTRD from 2018 to 2022. The primary outcome was the technical failure rate and their classification; secondary outcomes included subsequent management, clinical success, and complications. RESULTS: Included lesions were mainly recurrent (52 %), with a mean (SD) dimension of 18.4 (7.5) mm. Among 750 EFTRs, failures occurred in 77 patients (35 women; mean [SD] age 69.4 [8.9] years). A classification was proposed: type I, snare noncutting (53 %); type II, clip misdeployment (31 %); and type III, cap misplacement (16 %). Among endoscopic treatments completed, rescue endoscopic mucosal resection was performed in 57 patients (74 %), allowing en bloc and R0 resection in 71 % and 64 %, respectively. The overall adverse event rate was 27.3 %. Pooled estimates for the rates of failure, complications, and rescue endoscopic therapy were similar for low and high volume centers (P = 0.08, P = 0.70, and P = 0.71, respectively). CONCLUSIONS: Colorectal EFTR with the FTRD is a challenging technique with a non-negligible rate of technical failure and complications. Experience in rescue resection techniques and multidisciplinary management are mandatory in this setting.

Endoscopic powered resection device for residual colonic lesions: the first multicenter, prospective, international clinical study.

BACKGROUND AND AIMS: Endoscopic resection is standard treatment for adenomatous colorectal lesions. Depending on lesion morphology and resection technique, recurrence can occur. Scarred adenomas are challenging to resect and may require surgical management. This study evaluated the safety and effectiveness of an endoscopic powered resection (EPR) system for scarred adenomatous colorectal lesions. METHODS: This single-arm, prospective, multicenter study was conducted from January 2018 to January 2021 at 12 sites. Patients with persistent flat or sessile colorectal lesions were enrolled. Primary end points were technical success (the ability of the device to resect the lesion[s] without use of other resection devices without device-related serious adverse events [AEs]) and safety (the occurrence of AEs through 90 days). Secondary end points included endoscopic confirmation of resection completeness, occurrence of colon stenosis, disease persistence, and diagnostic value of resected specimens. RESULTS: Sixty-five patients were in the intention-to-treat/safety analysis population. Primary analysis was performed on 45 per-protocol (PP) patients with 48 lesions. All PP patients were solely treated by using the EPR device. Technical success was achieved in 44 (98%) patients. Three (5%) serious AEs occurred: 2 delayed self-limited bleeds and 1 perforation. Nonserious AEs included 4 (6%) cases of mild intraprocedural bleeding. Completeness of resection and histopathologic diagnosis of tissue specimens were achieved in all patients. Twenty-one (46.7%) patients had disease persistence after the first treatment, and there was no colon stenosis. CONCLUSIONS: EPR is safe and effective for benign, persistent, large (>20 mm), scarred colorectal adenomas and should be considered as an alternative treatment in lieu of surgery. A persistence rate of 46.7% indicates that >1 treatment is necessary for effective endoscopic treatment. (Clinical trial registration number: NCT04203667.).

The Colon Endoscopic Bubble Scale (CEBuS): a two-phase evaluation study.

BACKGROUND: To date, no scale has been validated to assess bubbles associated with bowel preparation. This study aimed to develop and assess the reliability of a novel scale - the Colon Endoscopic Bubble Scale (CEBuS). METHODS: This was a multicenter, prospective, observational study with two online evaluation phases of 45 randomly distributed still colonoscopy images (15 per scale grade). Observers assessed images twice, 2 weeks apart, using CEBuS (CEBuS-0 - no or minimal bubbles, covering < 5 % of the surface; CEBuS-1 - bubbles covering 5 %-50 %; CEBuS-2 - bubbles covering > 50 %) and reporting the clinical action (do nothing; wash with water; wash with simethicone). RESULTS: CEBuS provided high levels of agreement both in evaluation Phase 1 (4 experts) and Phase 2 (6 experts and 13 non-experts), with almost perfect intraobserver reliability: kappa 0.82 (95 % confidence interval 0.75-0.88) and 0.86 (0.85-0.88); interobserver agreement - intraclass correlation coefficient (ICC) 0.83 (0.73-0.89) and 0.90 (0.86-0.94). Previous endoscopic experience had no influence on agreement among experts vs. non-experts: kappa 0.86 (0.80-0.91) vs. 0.87 (0.84-0.89) and ICC 0.91 (0.87-0.94) vs. 0.90 (0.86-0.94), respectively. Interobserver agreement on clinical action was ICC 0.63 (0.43-0.78) in Phase 1 and 0.77 (0.68-0.84) in Phase 2. Absolute agreement on clinical action per scale grade was 85 % (82-88) for CEBuS-0, 21 % (16-26) for CEBuS-1, and 74 % (70-78) for CEBuS-2. CONCLUSION: CEBuS proved to be a reliable instrument to standardize the evaluation of colonic bubbles during colonoscopy. Assessment in daily practice is warranted.

Oral mannitol for bowel preparation: a dose-finding phase II study.

BACKGROUND: Successful bowel preparation (BP) for colonoscopy depends on the instructions, diet, the laxative product, and patient adherence, which all affect colonoscopy quality. Nevertheless, there are no laxatives which combine effectiveness, safety, easy self-administration, good patient acceptance, and low cost. However, mannitol, a sugar alcohol, could be an attractive candidate for use in clinical practice if it is shown to demonstrate adequate efficacy and safety. AIMS: The present phase II dose-finding study compared three doses of mannitol (50, 100, and 150 g) to identify the best dose to be used in a subsequent phase III study. METHODS: The Boston Bowel Preparation Scale, caecal intubation rate, adherence, acceptability, and safety profile, including measurement of potentially dangerous colonic gas concentrations (CH4, H2, O2), were considered in all patients. A weighted algorithm was used to identify the best mannitol dose for use in the subsequent study. RESULTS: The per-protocol population included 60 patients in the 50 g group, 54 in the 100 g group, and 49 in the 150 g group. The 100 g dose was the best as it afforded optimal colon cleansing efficacy (94.4% of patients had adequate BP), adherence, acceptability, and safety, including negligible gas concentrations. CONCLUSIONS: The present study demonstrated that the colon cleansing efficacy and safety of mannitol were dose dependent. Conversely, gas concentrations were not dose dependent and negligible in all patients. Combined evaluation of efficacy, tolerability, and safety, using a weighted algorithm, determined that mannitol 100 g was the best dose for the phase III study.

Novel 1-L polyethylene glycol + ascorbate versus high-volume polyethylene glycol regimen for colonoscopy cleansing: a multicenter, randomized, phase IV study.

BACKGROUND AND AIMS: Adequate bowel cleansing is critical to ensure quality and safety of a colonoscopy. A novel 1-L polyethylene glycol plus ascorbate (1L-PEG+ASC) regimen was previously validated against low-volume regimens but was never compared with high-volume regimens. METHODS: In a phase IV study, patients undergoing colonoscopy were randomized 1:1 to receive split-dose 1L PEG+ASC or a split-dose 4-L PEG-based regimen (4L-PEG) in 5 Italian centers. Preparation was assessed with the Boston Bowel Preparation Scale (BBPS) by local endoscopists and centralized reading, both blinded to the randomization arm. The primary endpoint was noninferiority of 1L-PEG+ASC in colon cleansing. Secondary endpoints were superiority of 1L-PEG+ASC, patient compliance, segmental colon cleansing, adenoma detection rate, tolerability, and safety. RESULTS: Three hundred eighty-eight patients (median age, 59.8 years) were randomized between January 2019 and October 2019: 195 to 1L-PEG+ASC and 193 to 4L-PEG. Noninferiority of 1L-PEG+ASC was demonstrated for cleansing in both the entire colon (BBPS ≥ 6: 97.9% vs 93%; relative risk [RR], 1.03; 95% confidence interval [CI], 1.001-1.04; P superiority = .027) and in the right-sided colon segment (98.4% vs 96.0%; RR, 1.02; 95% CI, .99-1.02; P noninferiority = .013). Compliance was higher with 1L-PEG+ASC than with 4L-PEG (178/192 [92.7%] vs 154/190 patients [81.1%]; RR, 1.10; 95% CI, 1.05-1.12), whereas no difference was found regarding safety (moderate/severe side effects: 20.8% vs 25.8%; P = .253). No difference in adenoma detection rate (38.8% vs 43.0%) was found. CONCLUSIONS: One-liter PEG+ASC showed noninferiority compared with 4L-PEG in achieving adequate colon cleansing and provided a higher patient compliance. No differences in tolerability and safety were detected. (Clinical trial registration number: NCT03742232.).

How to identify patients who are less likely to have metachronous neoplasms after a colon cancer: a predictive model.

BACKGROUND: Patients with prior colon cancer have increased risk of metachronous colorectal neoplasms; therefore, endoscopic surveillance is indicated. Current recommendations are not risk-stratified. We investigated predictive factors for colorectal neoplasms to build a model to spare colonoscopies for low-risk patients. METHODS: This was a multicenter, retrospective study including patients who underwent surgery for colon cancer in 2001 - 2008 (derivation cohort) and 2009 - 2013 (validation cohort). A predictive model for neoplasm occurrence at second surveillance colonoscopy was developed and validated. RESULTS: 421 and 203 patients were included in derivation and validation cohort, respectively. At second surveillance colonoscopy, 112 (26.6 %) and 55 (27.1 %) patients had metachronous neoplasms in derivation and validation groups; three cancers were detected in the latter. History of left-sided colon cancer (OR 1.64, 95 %CI 1.02 - 2.64), ≥ 1 advanced adenoma at index colonoscopy (OR 1.90, 95 %CI 1.05 - 3.43), and ≥ 1 adenoma at first surveillance colonoscopy (OR 2.06, 95 %CI 1.29 - 3.27) were independently predictive of metachronous colorectal neoplasms at second surveillance colonoscopy. For patients without such risk factors, diagnostic accuracy parameters were: 89.3 % (95 %CI 82.0 %-94.3 %) and 78.2 % (95 %CI 65.0 %-88.2 %) sensitivity, and 28.5 % (95 %CI 23.5 %-33.9 %) and 33.8 % (95 %CI 26.2 %-42.0 %) specificity in derivation and validation group, respectively. No cancer would be missed. CONCLUSIONS: Patients with prior left-sided colon cancer or ≥ 1 advanced adenoma at index colonoscopy or ≥ 1 adenoma at first surveillance colonoscopy had a significantly higher risk of neoplasms at second surveillance colonoscopy; patients without such factors had much lower risk and could safely skip the second surveillance colonoscopy. A prospective, multicenter validation study is needed.

Colon capsule versus CT colonography in patients with incomplete colonoscopy: a prospective, comparative trial.

OBJECTIVE: In case of incomplete colonoscopy, several radiologic methods have traditionally been used, but more recently, capsule endoscopy was also shown to be accurate. Aim of this study was to compare colon capsule endoscopy (CCE) and CT colonography (CTC) in a prospective cohort of patients with incomplete colonoscopy. DESIGN: Consecutive patients with a previous incomplete colonoscopy underwent CCE and CTC followed by colonoscopy in case of positive findings on either test (polyps/mass lesions ≥6 mm). Clinical follow-up was performed in the other cases to rule out missed cancer. CTC was performed after colon capsule excretion or 10-12 h postingestion. Since the gold standard colonoscopy was performed only in positive cases, diagnostic yield and positive predictive values of CCE and CTC were used as study end-points. RESULTS: 100 patients were enrolled. CCE and CTC were able to achieve complete colonic evaluation in 98% of cases. In a per-patient analysis for polyps ≥6 mm, CCE detected 24 patients (24.5%) and CTC 12 patients (12.2%). The relative sensitivity of CCE compared to CTC was 2.0 (95% CI 1.34 to 2.98), indicating a significant increase in sensitivity for lesions ≥6 mm. Of larger polyps (≥10 mm), these values were 5.1% for CCE and 3.1% for CTC (relative sensitivity: 1.67 (95% CI 0.69 to 4.00)). Positive predictive values for polyps ≥6 mm and ≥10 mm were 96% and 85.7%, and 83.3% and 100% for CCE and CTC, respectively. No missed cancer occurred at clinical follow-up of a mean of 20 months. CONCLUSIONS: CCE and CTC were of comparable efficacy in completing colon evaluation after incomplete colonoscopy; the overall diagnostic yield of colon capsule was superior to CTC. TRIAL REGISTRATION NUMBER: NCT01525940.

Validation of the diagnostic accuracy of probe-based confocal laser endomicroscopy for the characterization of indeterminate biliary strictures: results of a prospective multicenter international study.

BACKGROUND: Characterization of indeterminate biliary strictures remains problematic. Tissue sampling is the criterion standard for confirming malignancy but has low sensitivity. Probe-based confocal laser endomicroscopy (pCLE) showed excellent sensitivity in a registry; however, it has not been validated in a prospective study. OBJECTIVE: To prospectively validate pCLE in real time during ERCP for indeterminate biliary strictures. DESIGN: Prospective, international, multicenter study. SETTING: Six academic centers. PATIENTS: A total of 136 patients with indeterminate biliary strictures. INTERVENTIONS: Investigators provided a presumptive diagnosis based on the patient history, ERCP impression, and pCLE during the procedure before and after tissue sampling results were available. A presumptive diagnosis also was made separately by a blinded investigator during ERCP and after tissue sampling to estimate care without pCLE. Follow-up was at least 6 months. MAIN OUTCOME MEASUREMENTS: Accuracy, sensitivity, and specificity during ERCP alone, ERCP with pCLE, and ERCP with pCLE and tissue sampling. RESULTS: A total of 112 patients were evaluated (71 with malignant lesions). Tissue sampling alone was 56% sensitive, 100% specific, and 72% (95% confidence interval [CI], 63%-80%) accurate. pCLE with ERCP was 89% sensitive, 71% specific, and 82% (95% CI, 74%-89%) accurate. After tissue sampling returned, strictures could be characterized with 88% (95% CI, 81%-94%) accuracy. LIMITATIONS: No randomization of care maps. pCLE not blinded. CONCLUSION: pCLE provided a more accurate and sensitive diagnosis of cholangiocarcinoma compared with tissue sampling alone. Incorporation of pCLE into the diagnostic armamentarium of patients with indeterminate biliary strictures may allow for a more accurate assessment, potentially reducing delays in diagnosis and costly repeat testing. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT01392274.).

Factors influencing the presence of potentially explosive gases during colonoscopy: Results of the SATISFACTION study.

This study tested the hypothesis that bowel preparation with mannitol should not affect the colonic concentration of H2 and CH4 . Therefore, the SATISFACTION study, an international, multicenter, randomized, parallel-group phase II-III study investigated this issue. The phase II dose-finding part of the study evaluated H2 , CH4 , and O2 concentrations in 179 patients randomized to treatment with 50 g, 100 g, or 150 g mannitol. Phase III of the study compared the presence of intestinal gases in 680 patients randomized (1:1) to receive mannitol 100 g in single dose or a standard split-dose 2 L polyethylene glycol (PEG)-Asc preparation (2 L PEG-Asc). Phase II results showed that mannitol did not influence the concentration of intestinal gases. During phase III, no patient in either group had H2 or CH4 concentrations above the critical thresholds. In patients with H2 and/or CH4 levels above detectable concentrations, the mean values were below the risk thresholds by at least one order of magnitude. The results also highlighted the effectiveness of standard washing and insufflation maneuvers in removing residual intestinal gases. In conclusion, bowel cleansing with mannitol was safe as the concentrations of H2 and CH4 were the same as those found in patients prepared with 2 L PEG-Asc. In both groups, the concentrations of gases were influenced more by the degree of cleansing achieved and the insufflation and washing maneuvers performed than by the preparation used for bowel cleansing. The trial protocol was registered with ClinicalTrials.gov (https://clinicaltrials.gov/ct2/show/NCT04759885) and with EudraCT (eudract_number: 2019-002856-18).

Appropriateness of the indication for colonoscopy: is the endoscopist the 'gold standard'?

BACKGROUND: The appropriate selection of patients for colonoscopy is crucial for an efficient use of endoscopy. The role of endoscopist in filtering out inappropriate referrals is largely unknown. METHODS: A multicentre, prospective study was performed in which consecutive patients referred for colonoscopy during a 1-month period were enrolled. Before colonoscopy, the endoscopist assessed appropriateness of the endoscopic referral without directly consulting official guidelines, also collecting clinical and demographic variables. Appropriateness of the indication was eventually assessed by a group of experts based on the American Society for Gastrointestinal Endoscopy guidelines, representing the gold standard. Outcomes of the study were the inappropriateness rate and the main related causes, as well as the concordance rate between the endoscopists and the experts. A multivariate analysis was performed to identify predictors of inappropriateness. RESULTS: One thousand seven hundred ninety-nine patients were enrolled in 20 centres, of which 1489 outpatients were included in the final analysis. According to the American Society for Gastrointestinal Endoscopy guidelines, 432 referrals were inappropriate, corresponding to an inappropriateness rate of 29%. At multivariate analysis, prescription of a repeated colonoscopy (≥2 colonoscopies in the same patient) was strongly associated with the inappropriateness of the indication (odds ratio: 8.8; 95% confidence interval: 6.2, 12.7). Postpolypectomy or post-colorectal cancer surveillance accounted for 77% of the inappropriate control procedures. A 79% concordance rate between endoscopist and expert assessment was found. Among the 317 discordant cases, postpolypectomy or post-colorectal cancer surveillance accounted for 51% of the cases, the endoscopists mistakenly classifying it as appropriate in 55% to 61% of the inappropriate cases. CONCLUSIONS: Inappropriateness in outpatient colonoscopy referrals remains high, surveillance procedures representing the most frequent source of inappropriateness.

Early gastric cancer: detection and endoscopic treatment.

BACKGROUND: Early Gastric Cancer (EGC) is defined as a neoplasm confined to the mucosa or submucosa regardless of regional lymph node metastasis. The rate of EGC, which varies by country, is up to 40-60% of all gastric cancer cases in Japan, whilst in Western countries, the proportion remains at 5-10%. There is a strong male predominance in EGC. The average 5-year survival rate of patients with EGC reached over 90% in Japanese and European data. MATERIALS AND METHODS: Many EGC patients present with symptoms suggestive of a benign gastric ulcers. The combination of serum pepsinogen and Helicobacter pylori status may provide even more sensitive information for screening. However high-quality endoscopic evaluation with biopsy is the key to diagnosis. To improve the quality of observation several endoscopic imaging modalities have been developed for the diagnosis of early gastric cancer. Endoscopic resection is a viable alternative to surgery for curative treatment of EGC, with similar long term results. Endoscopic mucosal resection (EMR) of EGC without any risk of lymph node metastasis was developed in Japan in the 1980s, and it has been one of the standard treatments of EGC for nearly 20 years. Recently, several EMR techniques developed in Japan have been accepted and done in Western countries. These EMR techniques are safe and efficacious but unsuitable for large lesions. DISCUSSION: Because we could not remove a large lesion in 1 fragment, which was very important for the precise diagnosis of tumor depth, local recurrence increased in large-lesion cases. An innovative procedure using newly developed endoscopic knives, called endoscopic submucosal dissection (ESD), was developed in the late 1990s, which made it possible to remove a large lesion en bloc. CONCLUSION: Theoretically, ESD has no limitation with respect to tumor size; therefore, it is expected to replace the surgical treatment in some situations. Although ESD has spread throughout Japan within a short period, there remain several disadvantages, such as a higher incidence of complications and a requirement of higher endoscopic skills compared to those of conventional EMR methods.

Pharmacokinetics of oral mannitol for bowel preparation for colonoscopy.

This study aimed to define the pharmacokinetics (PKs) of oral mannitol used as an osmotic laxative for bowel preparation for colonoscopy. The PKs of oral mannitol was evaluated in a substudy as part of a phase II dose-finding, international, multicenter, randomized, parallel-group, endoscopist-blinded study. Patients were randomly assigned to take 50, 100, or 150 g mannitol. Venous blood samples were drawn at baseline (T0), 1 h (T1), 2 h (T2), 4 h (T4), and 8 h (T8) after completion of mannitol self-administration. The mean mannitol plasma concentrations (mg/ml) were dose-dependent with a consistent difference among doses. The mean maximum concentration (Cmax) ± SD was 0.63 ± 0.15, 1.02 ± 0.28, and 1.36 ± 0.39 mg/ml, in the three dosage groups, respectively. The mean area under the curve from zero to infinity (AUC0-∞) was 2.667 ± 0.668, 4.992 ± 1.706, and 7.403 ± 3.472 mg/ml*h in the 50, 100, and 150 g mannitol dose groups, respectively. Bioavailability was similar in the three dose groups and was just over 20% (0.243 ± 0.073, 0.209 ± 0.081, and 0.228 ± 0.093 in the 50, 100, and 150 g mannitol dose groups, respectively). The present study showed that the bioavailability of oral mannitol is just over 20% and is similar for the three tested doses (50, 100, and 150 g). The linear increase in Cmax, AUC0-t8, and AUC0-∞ must be considered when choosing the oral mannitol dose for bowel preparation to avoid its systemic osmotic effects.

Second-generation colon capsule endoscopy compared with colonoscopy.

BACKGROUND: Colon capsule endoscopy (CCE) represents a noninvasive technology that allows visualization of the colon without requiring sedation and air insufflation. A second-generation colon capsule endoscopy system (PillCam Colon 2) (CCE-2) was developed to increase sensitivity for colorectal polyp detection compared with the first-generation system. OBJECTIVE: To assess the feasibility, accuracy, and safety of CCE-2 in a head-to-head comparison with colonoscopy. DESIGN AND SETTING: Prospective, multicenter trial including 8 European sites. PATIENTS: This study involved 117 patients (mean age 60 years). Data from 109 patients were analyzed. INTERVENTION: CCE-2 was prospectively compared with conventional colonoscopy as the criterion standard for the detection of colorectal polyps that are ≥6 mm or masses in a cohort of patients at average or increased risk of colorectal neoplasia. Colonoscopy was independently performed within 10 hours after capsule ingestion or on the next day. MAIN OUTCOME MEASUREMENTS: CCE-2 sensitivity and specificity for detecting patients with polyps ≥6 mm and ≥10 mm were assessed. Capsule-positive but colonoscopy-negative cases were counted as false positive. Capsule excretion rate, level of bowel preparation, and rate of adverse events also were assessed. RESULTS: Per-patient CCE-2 sensitivity for polyps ≥6 mm and ≥10 mm was 84% and 88%, with specificities of 64% and 95%, respectively. All 3 invasive carcinomas were detected by CCE-2. The capsule excretion rate was 88% within 10 hours. Overall colon cleanliness for CCE-2 was adequate in 81% of patients. LIMITATIONS: Not unblinding the CCE-2 results at colonoscopy; heterogenous patient population; nonconsecutive patients. CONCLUSION: In this European, multicenter study, CCE-2 appeared to have a high sensitivity for the detection of clinically relevant polypoid lesions, and it might be considered an adequate tool for colorectal imaging.

PillCam colon capsule endoscopy: a prospective, randomized trial comparing two regimens of preparation.

GOAL: Aim of this study is to assess the feasibility of substituting sodium phosphate (NaP) with polyethylene glycol (PEG)-boosters in the protocol preparation for PillCam Colon Capsule Endoscopy (CCE). BACKGROUND: CCE represents a new diagnostic, endoscopic technology for colonic exploration. Bowel preparation for CCE is necessary not only to clean the colon, but also to promote capsule propulsion. For this reason, NaP boosters have been added to a 4 L PEG-preparation. NaP has been recently related with major side-effects. STUDY: Forty patients were prospectively randomized to Standard (n=20) or Modified (n=20) regimen. Standard regimen included clear liquid diet, 4 L of PEG, and 1 or 2 NaP boosters. In the Modified regimen, NaP boosters were substituted by 1 or 2 PEG boosters; 4 senna tablets and a low-residue diet were also included. Patients underwent CCE and conventional colonoscopy, carried out on the same day. CCE excretion rate, colon transit time, colon cleansing, and accuracy were evaluated. RESULTS: Hundred percent and 75% of CCE were excreted with the Standard and Modified regimen, respectively (P=0.02). Mean±SE colonic transit time of capsule was 2.17±1.43 hours in the Standard group, and 5.32±2.53 hours in the Modified group (P<0.001). Adequate preparation was achieved in 42.5% of the cases, without statistically significant difference between the 2 groups (35% vs. 53%; P=NS). CCE sensitivity and specificity for ≥6 mm polyps were 63% and 87%, without difference between the 2 groups. CONCLUSIONS: The exclusion of NaP booster from CCE preparation resulted into a clinically meaningful reduction of the capsule excretion rate that was only partially compensated by the PEG booster.

Update in biliary endoscopy.

Biliary endoscopy has seen the development of several new techniques in the last few years. Its current role includes direct diagnostic imaging, tissue sampling, early diagnosis and palliation of biliary tumors. Relatively new methods for biliary stones management are electrohydraulic lithotripsy combined with choledochoscope guidance and laser lithotripsy. Intraductal ultrasound, confocal laser endomicroscopy and optical coherence tomography are emerging, purely diagnostic endoscopic tools in biliary endoscopy. Cytological examinations such as digital imaging analysis and fluorescence in situ hybridization have the potential of becoming very important in the early diagnosis of biliary tumors. Direct visualization of the biliary mucosa and tissue sampling can be done with the last generation of cholangioscopes. All these tools are promising, especially for the 'undetermined biliary strictures'. Improvements in quality of life, survival and biliary drainage in patients with non-operable cholangiocarcinoma have been reported after the application of both photodynamic therapy and high-dose rate intraluminal brachytherapy. Drug-eluting stents with incorporated anti-tumor agents designed to improve patency and reduce the risk of tumor ingrowth have already been tested, and other stents are under investigation as well.

Small Bowel Capsule Endoscopy and artificial intelligence: First or second reader?

Several machine learning algorithms have been developed in the past years with the aim to improve SBCE (Small Bowel Capsule Endoscopy) feasibility ensuring at the same time a high diagnostic accuracy. If past algorithms were affected by low performances and unsatisfactory accuracy, deep learning systems raised up the expectancy of effective AI (Artificial Intelligence) application in SBCE reading. Automatic detection and characterization of lesions, such as angioectasias, erosions and ulcers, would significantly shorten reading time other than improve reader attention during SBCE review in routine activity. It is debated whether AI can be used as first or second reader. This issue should be further investigated measuring accuracy and cost-effectiveness of AI systems. Currently, AI has been mostly evaluated as first reader. However, second reading may play an important role in SBCE training as well as for better characterizing lesions for which the first reader was uncertain.

Artificial Intelligence in Lower Gastrointestinal Endoscopy: The Current Status and Future Perspective.

The present manuscript aims to review the history, recent advances, evidence, and challenges of artificial intelligence (AI) in colonoscopy. Although it is mainly focused on polyp detection and characterization, it also considers other potential applications (i.e., inflammatory bowel disease) and future perspectives. Some of the most recent algorithms show promising results that are similar to human expert performance. The integration of AI in routine clinical practice will be challenging, with significant issues to overcome (i.e., regulatory, reimbursement). Medico-legal issues will also need to be addressed. With the exception of an AI system that is already available in selected countries (GI Genius; Medtronic, Minneapolis, MN, USA), the majority of the technology is still in its infancy and has not yet been proven to reach a sufficient diagnostic performance to be adopted in the clinical practice. However, larger players will enter the arena of AI in the next few months.